Plaster and mortar mixer



1967 G. B. STONE ETAL 3,334,871

PLASTER AND MORTAR MIXER Filed April 18, 1966 INVENTOR. @LJTHF-ZIE B. STONE DQNALD E. SMITH ATTORNEY United States Patent 3,334,871 PLASTER AND MORTAR MIXER Guthrie B. Stone, Honeoye, and Donald E. Smith, Canandaigua, N.Y., assignors to Stone Conveyor Company, Inc., Honeoye, N.Y.

Filed Apr. 18, 1966, Ser. No. 543,220 1 Claim. (Cl. 259171) This invention pertains to plaster and mortar mixers and, more particularly, to an improvement in the cover guard therefor.

It is a general object of the invention to provide a plaster and mortar mixer having an automatic means for moving the cover guard to a position which will permit unrestricted flow of the mixed materials from the drum portion thereof.

A further object is that of providing such a mixer with linkage that will automatically pivot the cover guard outwardly when pivoting the drum of said mixer to empty the contents thereof, and which will move said guard into abutting relation with said drum as the latter is returned to operating position.

Further objects and advantages of the invention will become apparent from the following more detailed disclosure.

Plaster and mortar mixers to which the instant invention is applicable include a drum member which is substantially cylindrical and having therein a centrally disposed rotatable shaft. This shaft is journaled in the ends of the drum with one end thereof extending outwardly beyond one end of said drum where it is mechanically linked to any suitable source of power to effect rotation thereof. That portion of the shaft within the drum is provided with a plurality of angularly disposed paddles which rotate with the shaft and are effective in mixing the materials placed within the drum.

The drum itself is pivotable upon its axis and includes an opening in the upper portion thereof for introducing the materials to be mixed and for removing the mixed materials therefrom. The opening in the upper portion of the drum is provided with a cover guard of grill-like construction which is pivotably attached to one side of said opening and with the known forms of mixers, this cover guard must be manually pivoted away from the opening when the drum is pivoted or tilted to a position to permit an unrestricted flow of the mixed materials from the drum.

The means according to the instant invention for controlling the cover guard automatically causes said guard to pivot away from the opening when the drum is moved to a position for removal of the mixed materials and as the drum is being returned to operating or mixing position the guard moves back to cover the opening. This means includes a lever arm one end of which is pivotably attached to the cover guard at a point in spaced relation to that portion of the guard which is pivotably attached to the drum. The opposite end of the lever arm is pivotably attached to the supporting frame at a point relatively close to one of the pivot points of the drum. When the drum is in mixing position, the length of the lever arm is such as to maintain the cover guard in abutting relation with the opening and the pivot point of the lever arm not being on the same axial center as the drum, will cause the cover guard to be pivoted away from said opening as the drum is tilted to a position to allow the mixed materials to flow therefrom.

The invention will hereinafter be described in greater detail by reference to a specific embodiment thereof as illustrated in the accompanying figures of drawing, where- FIG. 1 is a view in end elevation of a portion of a plaster and mortar mixer showing by means of full and phantom lines the mixing and unloading positions, respectively, thereof and the manner in which the lever arm is caused to pivot the cover guard, and

FIG. 2 is a view in side elevation of the mechanism shown in FIG. 1.

Now referring to the figures of drawing, enough of a plaster and mortar mixer is shown in FIGS. 1 and 2 to serve as a basis for a detailed description of the invention applied thereto.

The drum portion of the mixer is identified generally by numeral 10 which is pivotably supported upon its axis by a supporting frame 11 as at 12. FIGS. 1 and 2 show only a portion of the supporting frame 11, and it should be understood that the drum is supported in 'a similar manner at its opposite end. The upper portion of the drum 10 is provided with an opening 13 for introducing the materials to be mixed and for removing the mixed materials from said drum. The drum is manually pivotable from the solid line to the phantom line positions shown in FIG. 1 by means of a handle 14 which is fixedly attached to the upper end portion of the drum and which is radially aligned with the axis of the latter.

A cover guard of grill-like construction which is depicted in FIGS. 1 and 2 by numeral 15 serves as a safety feature to cover the opening 13 when the drum member 10 is in mixing position.

This cover guard is hinged for pivotable movement to one side of the opening at as 16 and the shape thereof conforms generally to the configuration of the opening. Although only one side of the cover guard 15 is shown as being pivotably attached to the drum, it should be understood that its opposite side is hinged in a like manner.

The means for automatically moving the cover guard to the phantom line position shown in FIG. 1 will now be described.

A lever arm 17 as shown in FIG. 1 has one end thereof pivotably attached to the cover guard 15 at a point in spaced relation to the hinged portion thereof as at 18. The opposite end of this lever arm is pivotably attached to the supporting frame at a point relatively close to one of the pivot points of the drum as at 19. For maintenance purposes, the cover guard is quickly and easily released from the lever arm to allow said cover guard to be moved to a position clear of the opening 13. That portion of the lever arm which is pivotably attached to the cover guard is provided with a keyhole shaped aperture 20 and a pivot pin 21 which is fixedly attached to the cover guard extends through the smaller portion of the aperture forming the pivot point 18 heretofore described.

The head portion of pin 21 is larger than the smaller portion of the aperture and is effective in maintaining a pivotable connection between the cover guard and the lever arm.

To release the lever arm however, the guard is simply pivoted to a position which places the head of pin 21 in alignment with the larger portion of the aperture 20. This portion of the aperture being of a larger diameter than the head of the pin allows the lever to be pushed outwardly and clear of said pin.

In operation, the drum is in the solid line position shown in FIG. 1 and functions in a well-known manner to mix the materials contained therein. When tilting the drum to the phantom line position shown in this figure of drawing to remove the mixed materials, it is no longer necessary to manually pivot the cover guard to permit an unrestricted flow of said mixed materials from the drum.

The length of the lever arm and its pivot points relative to the axis of the drum are such as to maintain the cover guard in abutting relation with the opening when the drum is in mixing position. When the drum is tilted to the phantom line position shown in FIG. 1, the lever is effective in swinging the cover guard outwardly and away from that portion of the opening through which the mixed material are adapted to flow.

While one embodiment of the invention has been disclosed, it is to be understood that the inventive concept may be carried out in a number of ways. This invention is, therefore, not to be limited to the precise details described, but is intended to embrace all variations and modifications thereof falling within the spirit of the invention and the scope of the claim.

I claim:

In a mortar and plaster mixer having a supporting frame, a drum member pivotably supported on said supporting frame and an opening in said drum member for introducing materials to be mixed and for removing the mixed materials therefrom, a pivotable guard member hinged at one side of said opening and means for automatically pivoting said guard toward and away from said opening when pivoting said drum on its axis, said pivoting means including a lever arm having a first end thereof pivotably attached to said guard member and a second end pivotably attached to said supporting frame, said second end being disposed in spaced relation to the pivot point of said drum whereby the pivotable movement of said drum in one direction will move said guard away' References Cited UNITED STATES PATENTS 1,460,571 7/1923 Carey 259171 1,708,947 4/1929 Jaeger 259-109 1,848,223 3/1932 Reed 259l64 WILLIAM 1. PRICE, Primary Examiner.

R. W. JENKINS, Examiner. 

